Only hitting 3 lbs of boost and not going past 2800 rpm!! HELP!

Hey guys I have a blow thru setup on my 5.0 mustang with a Precision turbo and it will not go past 3-4 psi and will the engine will not go past 2800 rpm. Even if my foot is to the floor. I hear the turbo spooling but not all the way. It sounds like it want to scream but Nothing... Any ideas on what this is? Boost leak? Bov? Wg? Getting so frustrated I haven't heard this baby scream yet. Please help :/

yes i have a wideband and i have a precision 65 mm turbo, turbonetics evolution wastegate, turbo technologies intercooler, tial knockoff bov, holley 650 double pumper carb, stock fuel pump and the regulator i listed before. i keep hearing fuel delivery problem from people. the only reason i can think of why its doing this is because the regulator says it ranges from 3-12 psi which is not enough but its boost referenced